The invention pertains to refractory compositions. More particularly, the present invention relates to a refractory composition suitable for gunning, ramming or casting a monolithic structure.
When refractory mixes, particularly those for gunning, were first developed, the practice was to use conventional refractory bonds, such as sodium silicate or magnesium sulfate, as the bonding agent. While useful for their intended purpose, these mixes did not always exhibit maximum performance characteristics. For instance, if these mixes containing conventional bonding systems are used for gunning, there may arise some shortcomings since gunning mixes must mix readily with water, adhere well to a furnace wall without slumping or rebounding and must set to a coherent mass very rapidly. If these mixes containing conventional bonding systems are used for casting or ramming, they also may function well but increased performance is always desirable.
Accordingly, special bonding system have been developed.
U.S. Pat. No. 3,879,208 discloses a bonding system using aluminum sulfate.
U.S. Pat. No. 3,357,842 discloses a refractory composition containing monosodium dihydrogen orthophosphate as the bonding agent.
U.S. Pat. No. 3,357,843 discloses a bonding system using glassy polyphosphates, particularly sodium tripolyphosphate as the bonding agent.
U.S. Pat. No. 2,702,751 discloses a refractory composition containing magnesia, a chromium compound, for instance, chrome sulphate, and a boron compound.
U.S. Pat. No. 1,916,971 discloses a high temperature cement of aggregate, magnesium sulfate, and sodium citrate or citric acid.
U.S. Pat. No. 3,030,217 discloses a ramming mix of dead burned magnesite and an alkali metal salt of a monohydroxy aromatic monocarboxylic acid.
U.S. Pat. No. 3,333,972 discloses a refractory cementitious material of finely divided monoplastic magnesia and an organic acid, such as citric acid, or salt thereof.
U.S. Pat. No. 833,930 discloses a cement of magnesia, magnesium sulfate and a soluble salt of lead free from chlorine.
U.S. Pat. No. 3,360,388 discloses the use of boron compounds bonded with sodium silicate as the bonding agent in a refractory composition.
U.S. Pat. No. 2,619,426 discloses a refractory composition suitable for ramming, casting or pressing, or for use as mortar, and bonded with a combination of aluminum sulfate and calcium phosphate.
U.S. Pat. No. 4,276,901 discloses a refractory composition containing from 0.5 to 5% bentonite; from 1.5 to 10% of a bonding system consisting of from 1 to 5% alkali metal phosphates and from 0.5 to 5% aluminum sulfate; and up to 10% pitch.